Sea otters in the northern part of the Pacific Ocean are very ingeniously dealing with marine mollusks and crustaceans. When otters dive to the bottom to catch a crab, sea urchin, snail or mussel, he/she doesn't forget to take his/her favorite rock with him/her. He attaches it near the shore and uses the belt of the sea moss and weed, and while floating on his back, puts the rock on his stomach, as if it was an anvil. He also catches the snail or whatever with his forelimbs, and strikes it against the rock until the shell of the snail or a crab, for example, breaks and immediately swallows the meaty content from the middle. Very clever usage of rock to make the hard-to-eat food more accessible and quickly "on the table".